Examples

Complete working examples demonstrating QtNodes features.

Tip

All examples are in the examples/ directory. Build with -DBUILD_EXAMPLES=ON (default).

Gallery

	Calculator (examples/calculator/) Full data flow application with number sources, operators, and display. Demonstrates embedded widgets, save/load, and menu integration. Data Flow Model
	Simple Graph Model (examples/simple_graph_model/) Minimal custom graph model implementation. Shows how to subclass AbstractGraphModel and use BasicGraphicsScene. Graph Models
	Styles (examples/styles/) Custom styling with different color schemes and visual effects. Styling
	Connection Colors (examples/connection_colors/) Data-type-based connection coloring. Each data type has its own color. Styling
	Vertical Layout (examples/vertical_layout/) Top-to-bottom node arrangement with ports on top and bottom edges. Visualization
	Dynamic Ports (examples/dynamic_ports/) Add and remove ports at runtime. Shows the two-phase port modification API. Advanced Topics
	Resizable Images (examples/resizable_images/) Nodes with embedded image widgets that can be resized by dragging. Advanced Topics
	Lock Nodes & Connections (examples/lock_nodes_and_connections/) Prevent node movement and connection detachment. Advanced Topics
	Node Validation (examples/node_validation/) Demonstrates NodeValidationState and NodeProcessingStatus. Shows error/warning states and processing indicators. Data Flow Model
	Custom Painter (examples/custom_painter/) Custom node and connection rendering with gradients and arrows. Visualization
	Text (examples/text/) Simple text propagation between nodes. Good starting point. Data Flow Model

Headless Example

examples/calculator/headless_main.cpp demonstrates running computations without any GUI:

// Load a saved graph
DataFlowGraphModel model(registry);
model.load(loadJsonFromFile("saved_graph.json"));

// Modify inputs programmatically
auto* sourceNode = model.delegateModel<NumberSourceNode>(sourceNodeId);
sourceNode->setValue(42.0);

// Read computed output
auto* displayNode = model.delegateModel<DisplayNode>(displayNodeId);
double result = displayNode->getValue();

Running Examples

After building:

# From build directory
./bin/calculator
./bin/simple_graph_model
./bin/styles
# ... etc

Each example is a standalone executable demonstrating specific features.